2.18pm: The campaign group Avaaz, which helped coordinate the rescue of photographer Paul Conroy, claims that activists trapped in Baba Amr are preparing their wills in anticipation if a full-scale ground assault.

In a press statement it said:

Activists in other areas of Homs have now lost all contact with people inside the besieged neighborhood. Most of the city has been without electricity since 6pm last night.

The army renewed heavy shelling of Baba Amr and Insha'at early this morning. "The explosions are shaking the whole city of Homs," an activist in Khalidiyeh told Avaaz. The army has a stranglehold on the area, and according to one source in Homs has succeeded in entering Baba Amr's al-Hakourah district. There are reports of heavy clashes between the army and the FSA which Avaaz is seeking to verify.

The group also confirmed that Rastan, a town to the north of Homs is under renewed attack.

According to an activist in Rastan, the city is being bombarded from three sides. One home, belonging to the Farzat family, was hit several times while the family was inside. Activists could not reach the home to look for survivors.

• There are reports – difficult to confirm – that the Syrian regime's forces have launched a major ground offensive inside Homs. Communication with people in Homs has become very erratic. A Syrian official told the Associated Press that the Baba Amr district of Homs would be "cleaned" within hours.

Al-Jundi, a member of the Syrian National Council, told Reuters that he was injured in the city.

I was putting up flags in Karm al-Zeitoun with other activists in preparation for a rally when two soldiers came in a yellow taxi, got out and started shooting at us. They hit me in the leg. Two others with me were badly injured.

The sound of some shelling can be heard in the background. Jundi appeared in front of the camera to say there was a lull in the fighting, but then gunfire could be heard. He insisted it was safe to broadcast. Once again his location is unclear.

Reuters added:

The 26-year-old network engineer, who works in Saudi Arabia and is now on crutches, smuggled himself into Homs two weeks ago and has since been publishing photos and videos on his Facebook page on the destruction and victims of the bombardment.

Jundi said army shelling and rocket fire have intensified across Homs in the last few days.

"The shelling is mad," he said. "I was doing live Internet streaming yesterday when we heard the sound of tanks and saw them in the street behind us. We escaped to a different area. But nowhere is safe."

Asked where the weapons are bound, Abu Jihad [one of the dealers], who asked that his real name not be used, placed his hands over his eyes in a display of mock ignorance.

Then he says: "Everyone knows where the weapons are going - to the Jaish al-Hurr [Free Syrian Army]. At the end of the day, we are trying to make money and to look after our families … I say, just give me the money and take what you want. No problem."

A year ago, an RPG went for US$1,000 (Dh3,670), now it's $2,000. AK-47s have jumped from $1,500 to $2,300.

Technically, it is illegal in Lebanon to sell such weapons, but in a country that suffered through a 15-year civil war that ended in 1990 and still is afflicted by sectarian clashes, stocks are easy to come by.

1.09pm: Kofi Annan, the UN/Arab League envoy for Syria, said he will hold talks in New York from today with UN secretary-general Ban Ki-moon and member states, Reuters reports.

Annan, in a statement issued in Geneva where he is based, said he would hold a series of consultations in New York until Friday and then leave for Cairo to meet Arab League secretary-general Nabil Elaraby.

Annan, who served as UN secretary-general from 1997 to 2006, held separate talks in Geneva on Monday with Iranian foreign minister Ali Akbar Salehi and French foreign minister Alain Juppe.

In his first statement on Friday, he called for the full cooperation of all parties to help bring an end to Syria's violence and human rights abuses.

12.48pm: The foreign secretary William Hague says he backs attempts to draft a new UN resolution on Syria.

But writing on a Facebook group for foreign correspondents which he administers, Bouckaert said he could not confirm the start of a ground invasion.

There has been no communication with any of the activists in last 16 hrs or so, and no new videos uploaded by the activists. The last posts talked about very intense bombardment - they estimated they could hear 24 rounds hitting Baba Amro every 7 minutes. I don't have any confirmation of a ground assault but something bad is happening.

12.22pm: Syrian troops tried to enter the Baba Amr area yesterday but failed, according to a snatched conversation with an activist who claims to be in Homs.

Hadi Abdullah of the Syrian Revolution General Commission told AFP by telephone that it was a likely prelude to a final assault.

Access to Homs has now been completely sealed off, according to commanders of the rebel Free Syrian Army, who said the regular army had also blown up an underground aqueduct that had been the last viable route for smuggling in desperately needed supplies.

Abdullah said power had been cut to most of the city, a measure he said was another sign of possible looming attack.

12.04pm: Syria's first lady Asma Assad (pictured voting in Sunday's referendum) is reported to have claimed her family's situation is "excellent".

The source for this is very circuitous - an account of a telephone conversation between Asma Assad and Jordan's Queen Rania, published in London's al-Quds al-Arabi and translated by an Israeli news site.

"Every revolution has its Lady Macbeth," sighed one Middle East expert in Paris. The dictators' wives are all very different, united by the varying degrees of hatred they inspired, eye-watering fortunes, expensive wardrobes and often a state-sanctioned so-called "feminism" or, like Asma al-Assad, charity work as a public distraction against the brutal realities of the regime.

11.57am: Trying to confirm reports of a ground invasion in Homs is difficult.

A source in the city told one of my colleagues that there is no evidence of an infantry attack.

The International Committee of the Red Cross repeated its calls for a ceasefire.

A spokesman said:

We cannot confirm the offensive. In any case we are concerned over the consequences of the violence on the population as the humanitarian situation is worsening by the hour.

We repeat again our call for a cessation of fighting in order to help all those in need of help.

Although the ICRC managed to send aid to Homs yesterday it will be difficult to distribute it to those in need in the current conditions.

Alia Brahimi and George Joffe look at the regional implications of the turmoil in Syria and conclude:

If the Syrian regime is left unbridled by its more muscular global and regional friends or Russia and China abandon the negotiating option, Saudi Arabia seems likely to lead an Arab bloc (supported at least tacitly by Washington) in arming its opponents.

While new arms will surely enable a besieged population to better defend itself, they may well also instigate the "earthquake" threatened by Assad in October 2011. The Assad regime is determined to triumph, even if only through a Pyrrhic victory which could, in turn, explode throughout the region.

11.32am: Apologies for the lack of updates - information on the apparent assault on Baba Amr is hard to come by.

Activists claim Homs is under bombardment, but this is even harder than usual to confirm.

Gunfire and shelling can be heard on the feed. In the commentary Jundi he said the bombardment began at 6am this morning.

10.25am: There were reports yesterday – based on an unpublished interview – that President Moncef Marzouki of Tunisia is ready to offer asylum to Bashar al-Assad as part of a negotiated solution to end the Syrian conflict.

Marzouki's apparent hospitality towards Assad has not gone down well among all quarters in Tunisia, nor has his hosting of the international Friends of Syria gathering in Tunis last week.

The interviewer begins by asking Marzouki about demonstrations in Boussalem (a town north-west Tunis) where disgruntled protesters chanted: "The friends Boussalem rather than the friends of Syria."

Maarzouki shrugs that off with the words: "Listen, we went from a situation where people accepted and tolerated everything to a situation where people no longer accept or tolerate anything. I would say it is almost normal; after revolutions, the level of people's demands is extremely high. They feel free, they feel responsible, they have demands, and this is quite normal."

He is then asked about Tunisia's policy on Syria:

It was said that this meeting of "Friends of Syria" was a stab in the back of the Syrian people, and you have heard my speech: I said that Tunisia was totally against militarisation, totally against foreign intervention. I assure you that it did not please many people, but Tunisia is an independent country, so we make an independent diplomatic policy.

It is necessary to find a solution to let the dictator leave ... I very much regret that we are not in a logic of peace and the only logic for me is that, yes, one leaves an exit door for this dictator. Let him go where he wants, the essential part is that he leaves and stops killing people.

Asked if this would be based on the Yemeni model, he says:

Yes, according to the Yemeni model, it doesn't matter which country ... if he agreed to come to Tunisia, I guarantee that he would be given asylum. All that we want is that he stops killing Syrians. This is my one and only concern. Everything else is secondary.

I'd be willing to accept, without the slightest hesitation and give him all the guarantees. My only concern is that the killing of people stops. I cannot stand getting up every morning and watching the news and the death toll: 100 Syrians, 150 ... I find that unacceptable.

But during this intermediate phase, as we saw in Libya, there would perhaps be a need for a peacekeeping force that ensures the protection of minorities. Again, if our Syrian brothers don't ask for it, fine, I do think that we can have an Arab peacekeeping force and Tunisia would be very happy to participate.

10.08am: An activist told Reuters that troops have begun invading Baba Amr from the direction of al-Bassel football ground.

The presiding judge, Mohammed Shukri, made a formal request to renounce the case, without citing a reason, according to the TV report.

9.43am: Activists have again claimed ground invasion has began in the Baba Amr area or Homs, according to Reuters.

"The army is trying to go in with infantry from the direction of al-Bassel football field and fierce confrontations with automatic rifles and heavy machineguns are taking place there," activist Mohammad al-Homsi told Reuters from Homs.

He said the military had shelled the area heavily on Tuesday and overnight before the ground attack started.

Sunday Times journalist, Miles Amoore, who has been close to the negotiations to secure the release of wounded journalists from the area, tweeted:

In a statement Abdulrahman Attar, president of Syrian Arab Red Crescent, said:

These allegations are not only untrue, but are an affront to the sacrifices our staff and volunteers continue to make to gain access and provide humanitarian aid to all Syrian people in need, regardless of their nationality, religion, or political affiliation.

The repetition of unfounded allegations questioning the neutrality and trustworthiness of the SARC is not only undermining trust in the organisation and putting the lives of our staff and volunteers at risk, it is also hampering our efforts to deliver lifesaving aid on the ground, to all people in need.

They now unabashedly advocate for arming the Free Syrian Army. This is not an empty threat. The Saudis know how to procure and move weapons, and they have no shortage of cash. If Riyadh wants to arm the opposition, armed it shall be. And those who receive the weapons will likely be at least amenable to the Wahhabi interpretation of Islam that has spawned dangerous Islamist movements worldwide.

• Graphic video purporting to show the seven-day old corpses of the journalists Marie Colvin and Remi Ochlik have been broadcast by activists. The clip says the bodies are being kept in a refrigerator in Baba Amr in Homs. "Until now neither the Red Cross, the Red Crescent, nor any human rights organisation have come for them," a commentary on the clip claims. Colvin and Ochlik were killed in a rocket attack last week on a makeshift media centre in Baba Amr that wounded two other journalists.

Before this engagement, Avaaz.org had been criticised by some as "clicktivism" – implying a lazy form of protest involving little effort from its followers ...

Amid the bloodshed of Syria, the organisation's commitment is less likely to be queried. The question its critics are raising now is whether a group that started out in the high-tech safety of the internet has found itself out of its depth in a brutal conflict in the real world.

The idea that Assad's crimes against humanity might go unpunished is repugnant, but a face-saving exit plan, agreeable to all members of the international community – including Russia, China and Iran – might be the only way to remove Assad and set the country on the road to reform and democracy. The daily atrocities in Homs – like the terrifying attacks Gaddafi threatened in Benghazi – have, perfectly understandably, led to increased calls for military intervention.

The Metropolitan police, which is attempting to resist claims that it has been too close to Rupert Murdoch's News International, has confirmed it loaned Rebekah Brooks a police horse.

Brooks is the former chief executive of News International, who was forced to resign amid the phone-hacking scandal.

On Monday, the Leveson inquiry heard she had received extensive information from a police officer about the Met's first investigation into phone hacking, while News International was under criminal investigation.

The Met said the horse had reached the end of its working life and that there was nothing unusual in the decision to loan the horse, with Brooks being responsible for paying for its upkeep.

Brooks was loaned the horse in 2008, and it was kept at her home in Chipping Norton, Oxfordshire. Her husband, Charlie Brooks, is a trainer of racehorses.

In a statement, probably one of the odder ones it has issued, the Met said: "When a police horse reaches the end of its working life, Mounted Branch officers find it a suitable retirement home.

"Whilst responsibility for feeding the animal and paying vet bills passes to the person entrusted to its care at its new home, the horse remains the property of the Metropolitan police service.

"Retired police horses are not sold on and can be returned to the care of the MPS at any time.

"In 2008 a retired MPS horse was loaned to Rebekah Brooks. The horse was subsequently rehoused with a police officer in 2010."

The Met was already facing a rough ride at the Leveson inquiry over its failures to investigate News International's criminal activities.

The scale of phone hacking by the News of the World led Rupert Murdoch to close it down, and on Monday police said the Sun was being investigated for the bribing of public officials.